This invention relates to a method and an apparatus for intermittently stuffing a stuffing material into a casing, more particularly a method and an apparatus for stuffing the casing with a sausage stuffing material.
Conventionally, the operation of stuffing sausage meat into a casing has been carried out with equipment comprising of a stuffing device having a pump for pumping stuffing material through stuffing member, or stuffing tube, an upstream supplying device for supplying a desired portion of the casing to fill a sausage and a downstream supporting device for supporting a filled item.
Shirred casing, which are known in the trade as "sticks" or "hollow rods", are produced by gathering and longitudinally compressing long casing. In order to fill the shirred casing with a stuffing material, generally, one end of the shirred casing is first closed, and then the shirred casing is normally placed on the stuffing member. Stuffing material is then forced under pressure through the stuffing member into the casing which is continuously deshirred and supplied to a free end of the stuffing member. After a predetermined length of the casing has been filled, the filled casing is closed by twisting the casing at the free end of the stuffing member between supplying and supporting devices or is clip-closed by metallic clips or tied off by string.
For various reasons, the diameter of the sausages which are produced should remain constant throughout their entire length. Optimum filling of the tubular casing can be assured only of a uniform diameter, the size of which is dependent upon the extension of the filling casing. If the casing is overfilled, it may burst, whereas, if the casing is insufficiently filled, it will have a wrinkled surface.
Various methods and apparatuses for stuffing shirred tubular casing with sausage mixtures have been proposed in which special arrangements for deshirring, smoothing and breaking provides the optimum extension of the casing to achieve the most uniform diameter possible for the filled casing, and also provides some additional portion of the casing which is necessary for closing operation. Some of these preceding method and apparatuses do not provide a controllable degree of extension of the casing (U.S. Pat. No. 4,292,711). Some of these preceding devices provide a controllable degree of extension of the casing only outside of the working cycle during a maintenance (U.S. Pat. No. 3,872,543). The preceding apparatus which provides a controllable degree of extension of the casing during the working cycle have many driving parts (U.S. Pat. No. 4,442,568). This device operates without any connection with the extension of the filling casing. If the conditions of the filling are changed during the working cycle this device should be regulated manually.